Present tactical aircraft occasionally require more fuel than the internal fuel tanks of the aircraft can carry to perform its mission. These aircraft 50 (see FIG. 1) use external fuel tanks 52 supported by pylons 54 under the fuselage 56 or wings 58. These external fuel tanks 52 contain additional fuel that increases the aircraft's range and duration. Generally, the external fuel tanks 52 are jettisoned in combat. In peacetime, the external fuel tanks 52 are left on the aircraft due to the cost of storage and to reduce logistical problems. However, there are significant aerodynamic performance penalties associated with the carriage of the external fuel tanks 52. Resulting in increased aerodynamic drag and increased operation costs over the lifetime of the aircraft. In addition, the external fuel tank 52 is installed on a weapons pylon 54 reducing the weapons payload that can be carried by the aircraft 50.
Thus there exists a need for an expandable fuel cell that does not significantly increase the aerodynamic drag of the aircraft and does not reduce the weapons payload.